ABSTRACT
BACKGROUND@#The use of mouse bone marrow mesenchymal stem cells (mBMSCs) represents a promising strategy for performing preclinical studies in the field of cell-based regenerative medicine; however, mBMSCs obtained via conventional isolation methods have two drawbacks, i.e., (i) they are heterogeneous due to frequent macrophage contamination, and (ii) they require long-term culturing for expansion. @*METHODS@#In the present study, we report a novel strategy to generate highly pure mBMSCs using liposomal clodronate.This approach is based on the properties of the two cell populations, i.e., BMSCs (to adhere to the plasticware in culture dishes) and macrophages (to phagocytose liposomes). @*RESULTS@#Liposomal clodronate added during the first passage of whole bone marrow culture was selectively engulfed by macrophages in the heterogeneous cell population, resulting in their effective elimination without affecting the MSCs.This method allowed the generation of numerous high-purity Sca-1 ＋ CD44 ＋ F4/80 - mBMSCs ([ 95%) with just one passaging. Comparative studies with mBMSCs obtained using conventional methods revealed that the mBMSCs obtained in the present study had remarkably improved experimental utilities, as demonstrated by in vitro multilineage differentiation and in vivo ectopic bone formation assays. @*CONCLUSION@#Our newly developed method, which enables the isolation of mBMSCs using simple and convenient protocol, will aid preclinical studies based on the use of MSCs.
ABSTRACT
Objective To investigate the inducing effect of acitrotin on the growth and apoptosis of human cutaneous squamous cell carcinoma cell line SCC13 and on caspases expression.Methods Human cutaneous squa-mous cell carcinoma cell line SCC13 was treated with five different concentrations of acitrefin [5×10-7,1×10-6,5×10-6,1×10-5,5×10-5mol/L].Cell proliferation was evaluated by MTT assay.Apoptosis was assessed by en-zyme-linked immunosorbent assay.The cell cycle was assessed by flow cytometry.The protein expressions of caspase-8 and caspase-9 were examined with Western blot.Results Acitretin inhibited the growth ( F = 83.64,96.34 and 123.17, respectively on the first, third and fifth day)and induced the apoptosis of SCC13 cells(F=74.45,107.37,and 64.28, respectively on the first, third and fifth day) in a dose- and time-dependent manner(P<0.05).Acitretin altered cell cycle distribution of SCC13 cells as compared with controls, the G1-phase population increased by 77.66% 72 hours after acitretin treatment, while the control increased only by 63.55%.An active fragment of caspase-8 occurred following 12 hours treatment of acitretin on SCC13 cells, whereas the caspase-9 active fragment occurred 24 hours after acitretin treatment, which increased time-dependently (P<0.01).Conclusion Acitretin plays an important role on the growth inhibition and apoptosis of cutaneous squamous cell carcinoma cells, which may be affected through both Fas receptor way and mitochondria way.
ABSTRACT
Objective To explore the mechanism of aluminum-induced damage of learning and memory by studying the change of calcium-calmodulin-dependent protein kinase Ⅱ(CaMKⅡ) in the hippocampus of lactational rats. Methods Three groups of clean pregnant Wistar rats (120-200 g) were randomly divided into 3 groups. On the first day of parturition, the dams of two groups were given 0.3% and 0.6% AlCl3 through drinking water and terminated on the weaning day (21 days). Western blot was used to determine the content and activity of ?-CaMKⅡ. Results The aluminum levels in the blood and brain of aluminum-treated rats were obviously higher than that in the control (P